This invention relates to a functional polymer comprising active and stable functional groups, and to a method of preparing the same. More particularly, the present invention relates to a functional polymer that comprises repeat units having structures corresponding to end products of cycloaddition between polymeric 1-(vinylphenyl)ethylene repeat units and an electron-poor alkene, and also to the cycloaddition method of its preparation.
Functional polymers are widely used in industry as separation media and as solid-phase reagents, catalysts and protecting groups for analytical or preparative chemical applications and processes [D. C. Sherrington and P. Hodge, xe2x80x9cSyntheses and Separations Using Functional Polymersxe2x80x9d, John Wiley and Sons, Toronto, 1988]. A functional polymer generally consists of a polymer matrix, in the form of particles, beads or a porous block [C. Viklund, F. Svek, J. M. J. Frxc3xa9chet and K. Irgum, xe2x80x9cMolded porous materials with high flow characteristics for separation or catalysis: control of porous properties during polymerization in bulk solutionxe2x80x9d, Chem. Mater. y1986 v8 p744-750], that is chemically inert to the conditions of its use, including being insoluble in any solvent it is likely to encounter so that it can be retained in a column or easily recovered from out of a product mixture by filtration or other separation for easy isolation of chemical product and reuse of the functional polymer; and also of functional groups, attached to the polymer matrix, that can bind, transform or otherwise interact with chemical species that are dissolved in a permeating fluid, or that confer other advantageous properties to the functional polymer, such as a higher density for best use in floating bed reactors or for easier and faster separation by precipitation, or better wetting and penetration by a particular solvent. Most often, the polymer matrix is of crosslinked polystyrene, due to the ease of its preparation through suspension or other polymerization of styrene or styrene-like monomer (usually, including divinylbenzene as crosslinking agent), with attendant control of particle size, porosity, swellability, surface area, and other aspects of its architecture affecting eventual use; and its good general mechanical and chemical stabilities, though also with the ability to be controllably decorated with any of a wide variety of functional groups. In ion exchange resins, which are manufactured in large quantities for deionizing water and many other purification processes, these functional groups may consist of sulfonic, carboxylic or phosphonic acids or their salts, or amines or their salts, or quaternary ammonium or phosphonium hydroxides or other of their salts; chelating resins that recover toxic or expensive metal ions from wastewater may contain combinations of amino and sulfonate, phosphonate or carboxylate groups, along with hydroxyl, ether, thiol, sulfide, phosphine or other Lewis base groups; certain of these groups may also coordinate with metal ions to activate their negative counterions for phase transfer catalyzed nucleophilic substitution or other reactions, or may hold platinum or other catalytic heavy metal species so that these are conserved and re-used from one reaction to the next; halosilyl, haloalkyl, haloacyl or halosulfonyl functional groups, or anhydride or azlactone functional groups, can covalently bind to other organic molecules so that parts of these are protected while other parts are being chemically modified, the whole later released, such as in solid-phase synthesis of polypeptides, polysaccharides or polynucleotides, or themselves act as agents for catalysis or molecular recognition, as with enzymes, antibodies or antigens that have been polymer-bound. Halogen-rich functional groups can improve sorption in a functional polymer [Specialty Polymers Division, xe2x80x9cManual of ion exchange resins and synthetic adsorbentxe2x80x9d, Mitsubishi Kasei Corporation: Tokyo, Japan y1991 v1 p123-1321], and increase its fire-resistance, and density for separation by precipitation, while ferrous/ferric oxide precipitated around carboxylate groups can allow polymer particles to be recovered magnetically from mixtures [J. Ugelstad, U.S. Pat. No. 4,654,267 y1987].
While functional polymers may be prepared by polymerization of monomers that already contain the desired functional groups, more commonly they are made by chemically functionalizing or modifying other existing polymer matricesxe2x80x94most commonly, crosslinked polystyrenexe2x80x94as prepared from common monomers through established polymerization recipes that give well-defined and desirable particle and matrix structures and properties. However, existing such modification methods of preparing functional polymers often suffer from disadvantages of hazardous or expensive ingredients or conditions, that result in products that are intrinsically deficient in activity or stability or both [G. D. Darling and J. M. J. Frxc3xa9chet xe2x80x9cDimethylene spacers in functionalized polystyrenesxe2x80x9d, in J. L. Benham and J. F. Kinstle, Eds. xe2x80x9cChemical Reactions on Polymersxe2x80x9d, ACS Symp. Ser. v364, American Chemical Society, Washington DC, y1988 p24-36]. For example, the chloromethylation route to the most common anion-exchange and chelating polystyrene-based resins uses or generates highly carcinogenic species, and results in benzyl-heteroatom bonds that are unstable to many conditions of eventual use or regeneration; bromination/lithiation, another general route to functional polymers, employs expensive and sensitive organometallic reagents and, like sulfonation, results in aryl-heteroatom functional groups that may be unstable in acidic conditions. Functional polymers containing aliphatic spacer groups of at least two carbons between polystyrene phenyl and functional group heteroatom would not show either type of chemical instability, and moreover, the deeper penetration of their dangling functional groups into a fluid phase permeating the polymer matrix often allows better and faster interactions with soluble species therein [A. Deratani, G. D. Darting, D. Horak and J. M. J. Frxc3xa9chet xe2x80x9cHeterocyclic polymers as catalysts in organic synthesis. Effect of macromolecular design and microenvironment on the catalytic activity of polymer-supported (dialkylamino)pyridine catalysts.xe2x80x9d Macromolecules y1987 v20 p767]. Several such spacer-containing functional polymers have been prepared via electrophilic aromatic substitutionxe2x80x94either chloromethylation or bromination/lithiationxe2x80x94of aryl nuclei in crosslinked styrene-divinylbenzene copolymer, albeit through tedious multistep syntheses [Darling and Frxc3xa9chet y1988 ibid].
Instead of on styrenic phenyl, modification reactions can be performed on the vinyl groups of polymeric 1-(vinylphenyl)ethylene repeat units. These vinyl groups may be prepared from formyl, chloromethyl, bromoethyl or 1,2-dibromoethyl functional group precursors [M. J. Farrell, M. Alexis and M. Trecarten, Polymer y1983 v24 p114; Darling and Frxc3xa9chet y1988 ibid; T. Yamamizu, M. Akiyama and K. Takeda, React. Polym. y1985 v3 p173], or remain from anionic [Y. Nagasaki, H. Ito, T. Tsuruta, Makromol. Chem. y1968 v187 p23] or even free-radical [M. C. Faber, H. J. van den Berg, G. Challa and U. K. Pandit, React. Polym. y1989 v11 p117] copolymerization of monomer mixtures that include divinylbenzene. Radical copolymerization with divinylbenzene is a particularly simple way to form a polymer that contains such vinyls, that moreover have here the advantage of being site-isolated; indeed, Rohm and Haas supplies a commercial product, xe2x80x9cAmberlite(copyright) XAD-4 nonionic polymeric adsorbentxe2x80x9d, which analysis thereof indicates to be undoubtedly made by radical copolymerization of a mixture of divinylbenzene and ethylstyrenexe2x80x94which mixture, containing both meta and para isomers of each, is commercially provided under the name xe2x80x9ctechnical-grade divinylbenzenexe2x80x9d [xe2x80x9cAldrich Catalogxe2x80x9d y1997], and so which resulting polymer may be called xe2x80x9cpoly(divinylbenzene)xe2x80x9dxe2x80x94and which contains 30 mol % of polymeric 1-(vinylphenyl)ethylene repeat units, with the remaining repeat units consisting of polymeric 1-(ethylphenyl)ethylene and crosslinking polymeric bis(ethylene)phenyl repeat units [Faber et al y1989 ibid]. Through electrophilic, nucleophilic, radical, transition-metal catalyzed or other additions to such polymeric 1-(vinylphenyl)ethylene repeat units [W. Obrecht, Y. Seitz and W. Funke, Makromol. Chem, y1976 v177 p2235; Faber et al y1989 ibid; Z. Zhengpu, P. Hodge and P. W. Stratford, React. Polym. y1991 v15 p71; J. P. Gao, F. G. Morin and G. D. Darling, Macromolecules y1993 v26 p1196], or by their radical-induced graft copolymerizations with various monomers [T. Brunelet, M. Bartholin and A. Guyot, Angew. Makromol. Chem. y1982 v106 p79], have been provided a wide variety of functional groups, including of the form Ps-CH2xe2x80x94CH2xe2x80x94X, wherein Ps represents a crosslinked polystyrene matrix connecting through phenyl, and X a functional group connecting through a heteroatom, that features advantageous dimethylene spacer [Gao et al y1993 ibid].
Useful electron-withdrawing functional groups such as halo or carboxylate may be incorporated into functional polymers through polymerizations with haloalkene, acrylic, methacrylic, maleate or fumarate comonomers. As previously mentionned though, modification of an existing optimal polymer matrix is a route often to be preferred for its simplicity, versatility, economy and better product properties. Though individual molecules of such electron-poor alkenes as maleic anhydride have been grafted onto uncrosslinked polymers to provide functionality for crosslinking and other modifications, or improve adhesion, hydrophilicity, and compatibility with other materials, both onto saturated polyalkanes like polyethylene and polypropylene in the presence of free radicals [S. W. Caywood Jr., U.S. Pat. No. 3,884,882, y1975], and onto xe2x80x94CH less than -substituted alkene groups left in conjugated diene copolymers by non-radical ene reactions [B. C. Trivedi and B. M. Culbertson, xe2x80x9cMaleic Anhydridexe2x80x9d, Plenum: New York, 1982, Chapter 11]; and though non-polymeric vinylphenyl compounds have been made to undergo cycloadditions with maleic anhydride [Joseph Csapilla, U.S. Pat. No. 5,414,094, y1995] and hexachlorocyclopentadiene [M. Look, Aldrichim. Acta y1974 v7 p2314 29]; and though the products of cycloaddition between polymeric (1-vinylphenyl)ethylene repeat units and electron-poor alkenes would provide a wide variety of useful functional groups on attractive and controllable polymer matrices, derived via relatively simple procedures from available starting materialsxe2x80x94the prior art has no examples of polymeric (1-vinylphenyl)ethylene groups being modified by cycloadditions with the forementionned or any other alkenes, nor are the useful products that would be characteristic of such reactions known by any other route.
It is an object of this invention to provide a functional polymer comprising repeat units having structures corresponding to end products of cycloaddition of polymeric 1-(vinylphenyl)ethylene repeat units with an electron-poor alkene for separation or reactive processes in chemical manufacture or analysis.
It is another object of this invention to provide a functional polymer that can be prepared using readily-available materials and simple conditions and apparatus.
It is another object of this invention to provide a functional polymer, the architecture of whose polymer matrix (e.g. particle size and shape, porosity, swellability, surface area), and type, arrangement and number of whose functional groups, can be controlled.
It is another object of this invention to provide a functional polymer whose functional groups are stable, active, and accessible to a permeating fluid.
It is another object of this invention to provide a functional polymer bearing functional groups that are halo, heterocycle, carboxylic anhydride, carboxyl halide, carboxylic acid, carboxylate salt, ester, amide, imide, or polymer-supported ion, polynucleotide, polypeptide, polysaccharide, enzyme, antibody or antigen, or combinations thereof, in type, arrangement and number sufficient to confer or contribute towards acidity, basicity, ion exchange, fire-resistance, wettability, chelation, extraction, separation, sorption, density, permeability, catalysis, selectivity, hydrophilicity, reactivity, seperability, suspendability, binding of ions, binding of organic molecules, binding of polypeptides, binding of polysaccharides, binding of polynucleotides, molecular recognition, filterability, convertability to other functional groups, or other desirable qualities, or combinations thereof, in a separation medium, chromatographic medium, purification medium, ion-exchange medium, chelating medium, solid-phase reagent, solid-phase catalyst, solid-phase protecting agent, support for solid-phase synthesis, chemical intermediate, or other application of a functional polymer, or combinations thereof.
In accordance with the invention there is provided a functional polymer that comprises repeat units having structures corresponding to end products of cycloaddition between polymeric 1-(vinylphenyl)ethylene repeat units and an electron-poor alkene.
In accordance with another aspect of the invention there is a provided a functional polymer that can be prepared by heating a preexisting polymer comprising polymeric 1-(vinylphenyl)ethylene repeat units with an electron-poor alkene, without need of radicals or exclusion of oxygen.
In accordance with a preferred embodiment of the invention there is provided a method of preparing a functional polymer, by heating a polymer that comprises polymeric 1-(vinylphenyl)ethylene repeat units with an electron-poor alkene dissolved in a fluid that permeates said polymer.
In accordance with a preferred embodiment of the invention there is provided a functional polymer that has been prepared by heating a pre-existing polymer comprising polymeric 1-(vinylphenyl)ethylene repeat units with an electron-poor alkene.
In accordance with a preferred embodiment of the invention there is provided a functional polymer that comprises repeat units having structures corresponding to end products of cycloaddition between polymeric 1-(vinylphenyl)ethylene repeat units and an electron-poor alkene, that were derived by chemical modification of structures corresponding to end products of cycloaddition between polymeric 1-(vinylphenyl)ethylene repeat units and another electron-poor alkene.
In accordance with a preferred embodiment of the invention there is provided a functional polymer that comprises repeat units having structures corresponding to end products of cycloaddition between polymeric 1-(vinylphenyl)ethylene repeat units and an electron-poor alkene, that were derived by reaction of a nucleophile with structures corresponding to end products of cycloaddition between polymeric 1-(vinylphenyl)ethylene repeat units and maleic anhydride.
In accordance with a preferred embodiment of the invention there is provided a functional polymer that comprises repeat units having structures corresponding to end products of cycloaddition between polymeric 1-(vinylphenyl)ethylene repeat units of a radical copolymer of monomers comprising divinylbenzene, and an electron-poor alkene.
In accordance with a preferred embodiment of the invention there is provided a functional polymer that comprises repeat units having structures corresponding to end products of cycloaddition between polymeric 1-(vinylphenyl)ethylene repeat units of a radical copolymer of monomers consisting of meta-divinylbenzene and para-divinylbenzene and meta-ethylstyrene and para-ethylstyrene, and an electron-poor alkene.
In accordance with a preferred embodiment of the invention there is provided a functional polymer that comprises repeat units having structures corresponding to end products of cycloaddition between polymeric 1-(vinylphenyl)ethylene repeat units and an alkene, wherein one or more of the olefinic carbons thereof are substituted with groups that withdraw electrons by induction or resonance.
In accordance with a preferred embodiment of the invention there is provided a functional polymer that comprises repeat units having structures corresponding to end products of cycloadditioh between polymeric 1-(vinylphenyl)ethylene repeat units and a conjugated diene capable of cisoid conformation, wherein one or more of the olefinic carbons thereof are substituted with groups that withdraw electrons by induction or resonance.
In accordance with a preferred embodiment of the invention there is provided a functional polymer that comprises repeat units having structures corresponding to end products of cycloaddition between polymeric 1-(vinylphenyl)ethylene repeat units and an electron-poor alkene, said end products having incorporated one mole of said alkene per said repeat unit.
In accordance with a preferred embodiment of the invention there is provided a functional polymer that comprises repeat units having structures corresponding to end products of cycloaddition between polymeric 1-(vinylphenyl)ethylene repeat units and an electron-poor alkene, said end products having incorporated two moles of said alkene per said repeat unit.
In accordance with a preferred embodiment of the invention there is provided a functional polymer that comprises repeat units having structures corresponding to end products of cycloaddition between polymeric 1-(vinylphenyl)ethylene repeat units and an electron-poor alkene selected from maleic anhydride, maleimide, N-alkylmaleimide wherein xe2x80x9calkylxe2x80x9d is selected from methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, s-butyl and t-butyl; of the form Xxe2x80x94COxe2x80x94CHxe2x95x90CHxe2x80x94COxe2x80x94Y whose geometry is selected from cis and trans and wherein X and Y are selected from Cl, Oxe2x88x92, OR1 and NR1R2 wherein R1 and R2 are selected from H, Me, Et, nPr, iPr, nBu, iBu, sBu, tBu, an amino acid residue of a polypeptide a carbohydrate residue of a polysaccharide, and a nucleotide residue of a polynucleotide; hexachlorocyclopentadiene, and 3,6-di-2-pyridyl-1,2,4,5-tetrazine.
In accordance with a preferred embodiment of the invention there is provided a functional polymer that comprises repeat units having structures corresponding to end products of cycloaddition between polymeric 1-(vinylphenyl)ethylene repeat units and an electron-poor alkene, which said functional polymer also comprises other functional groups.
In accordance with a preferred embodiment of the invention there is provided a functional polymer that comprises repeat units having structures corresponding to end products of cycloaddition between polymeric 1-(vinylphenyl)ethylene repeat units and an electron-poor alkene, which said functional polymer also contains magnetic iron oxide.
In accordance with a preferred embodiment of the invention there is provided a functional polymer that comprises repeat units having structures corresponding to end products of cycloaddition between polymeric 1-(vinylphenyl)ethylene repeat units and an electron-poor alkene, said structures comprising one or more functional groups selected from halo, heterocycle, carboxylic anhydride, carboxyl halide, carboxylic acid, carboxylate salt, ester, amide, imide, or polymer-supported ion, polynucleotide, polypeptide, polysaccharide, enzyme, antibody or antigen; which said functional groups are in type, arrangement and number to confer or contribute towards one or more qualities in said functional polymer selected from acidity, basicity, ion exchange, fire-resistance, wettability, chelation, extraction, separation, sorption, density, permeability, catalysis, selectivity, hydrophilicity, reactivity, separability, suspendability, binding of ions, binding of organic molecules, binding of polypeptides, binding of polysaccharides, binding of polynucleotides, molecular recognition, filterability, or convertability to other functional groups; which qualities are such as to allow or improve for one or more uses selected from separation medium, chromatographic medium, purification medium, ion-exchange medium, chelating medium, solid-phase reagent, solid-phase catalyst, solid-phase protecting agent, support for solid-phase synthesis, and chemical intermediate.